3.0 Dolphin

OT: Who double clutches when downshifting? If not, do you jerk when releasing clutch?

Ash

...fast at it. I'm not sure what you mean by jerking when I release the clutch...you mean when the final stage of the double clutch downshift is complete, the gear is in and I'm letting the clutch out? Well that depends on if my rev-matching was good enough and if I "caught" it in time...I'm pretty used to it now so I can do it smoothly most times...

Ash

MikekiM@PureMS

You're referring to rpm matching which is common. Dbl clutching isn't necessary on syncho'd tranny

3.0 Dolphin

then do you jerk upon "releasing the clutch," or do the synchros take care of the transition to a lower gear?

Er-excess-4

I was just matching revs before by blipping the throttle with clutch depressed and that worked well also. Is what MikekiM posted true?? It's more fun to double clutch but hey if it's not nessesary, then why risk the extra wear on the clutch??

JCJiffy

I heel-and-toe when downshifting, but I don't double-clutch because it's not necessary w/ synchros.

MikekiM@PureMS

That's they're whole purpose, to allow you to shift gears, without the need to match transmission rotation with flywheel rotation. They allow you to slip the tranny into gear, regardless of how fast the engine, or tranny are spinning.

Ash

..regardless of wether you're double clutching or not. As MikekiM said above, I think you're referring to rpm matching which needs to be done regardless of your downshift technique.

The synchros role in this is not to match engine rpm to gear rpm, but it is to match up the layshaft rpm to gear rpm which is internal to the transmission. On old transmissions without sychros, you would HAVE to double clutch to downshift otherwise you would get GRINDING in the gearbox. So synchros prevent grinding, but don't help you match engine rpms to gear rpms.

Hope I've not confused the issue even more...

Ash

MikekiM@PureMS

is the flywheel slowing down, or speeding up, to match the speed of the tranny. Blipping the throttle when downshifting can help minimize that effect. Some people may call this heel/toe which produces the same effect. Double clutching is sort of related to what causes the jerk, (mismatched engine/tranny speed), but it's purpose isn't to prevent jerks, but to allow the tranny to actually engage a gear.

Ash

...because first of all I don't think the synchros on our A4 gearboxes are the best in the business (do an archive search on gears grinding on downshifts and you'll see what I mean), and double clutching lessens the wear on the synchros as you're helping them in their function.

And since our synchros (esp. on 2nd gear) need all the help they can get, I double clutch on downshifts in order to keep the motion of going into the gear (i.e. me moving the gear lever down into 2nd say) a smooth and grind-free process. Try doing this and you'll see how nice and easy the gear shifter goes down into gears...if you double clutch just right. It's addictive to get the double clutch just right and execute a perfect downshift...that's why I do it all the time.

Ash